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path: root/arch/sparc64/kernel/etrap.S
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2008-05-20sparc64: remove CVS keywordsAdrian Bunk
This patch removes the CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-11sparc: Fix debugger syscall restart interactions.David S. Miller
So, forever, we've had this ptrace_signal_deliver implementation which tries to handle all of the nasties that can occur when the debugger looks at a process about to take a signal. It's meant to address all of these issues inside of the kernel so that the debugger need not be mindful of such things. Problem is, this doesn't work. The idea was that we should do the syscall restart business first, so that the debugger captures that state. Otherwise, if the debugger for example saves the child's state, makes the child execute something else, then restores the saved state, we won't handle the syscall restart properly because we lose the "we're in a syscall" state. The code here worked for most cases, but if the debugger actually passes the signal through to the child unaltered, it's possible that we would do a syscall restart when we shouldn't have. In particular this breaks the case of debugging a process under a gdb which is being debugged by yet another gdb. gdb uses sigsuspend to wait for SIGCHLD of the inferior, but if gdb itself is being debugged by a top-level gdb we get a ptrace_stop(). The top-level gdb does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the signal. But ptrace_signal_deliver() assumed the debugger would cancel out the signal and therefore did a syscall restart, because the return error was ERESTARTNOHAND. Fix this by simply making ptrace_signal_deliver() a nop, and providing a way for the debugger to control system call restarting properly: 1) Report a "in syscall" software bit in regs->{tstate,psr}. It is set early on in trap entry to a system call and is fully visible to the debugger via ptrace() and regsets. 2) Test this bit right before doing a syscall restart. We have to do a final recheck right after get_signal_to_deliver() in case the debugger cleared the bit during ptrace_stop(). 3) Clear the bit in trap return so we don't accidently try to set that bit in the real register. As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just like sparc64 has. M68K has this same exact bug, and is now the only other user of the ptrace_signal_deliver hook. It needs to be fixed in the same exact way as sparc. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-23[SPARC64]: Store magic cookie and trap type in pt_regs.David S. Miller
This sets us up for several simplifications and facilities: 1) The magic cookie lets us identify trap frames more accurately in stack backtraces. 2) The trap type lets us simplify all of the "are we in a syscall" state management and checks. 3) We can now see if a task off the cpu is sleeping in a system call or not. In fact, we can see what trap it is sleeping in whatever the type. The utrace guys will use this. Based upon some discussions with Roland McGrath. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-20[SPARC64]: Fix tl1 trap state capture/dump on SUN4V.David S. Miller
No trap levels above 2 in privileged mode on SUN4V. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Patch up mmu context register writes for sun4v.David S. Miller
sun4v uses ASI_MMU instead of ASI_DMMU Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Rename gl_{1,2}insn_patch --> sun4v_{1,2}insn_patchDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Add initial code to twiddle %gl on trap entry/exit.David S. Miller
Instead of setting/clearing PSTATE_AG we have to change the %gl register value on sun4v. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fill dead cycles on trap entry with real work.David S. Miller
As we save trap state onto the stack, the store buffer fills up mid-way through and we stall for several cycles as the store buffer trickles out to the L2 cache. Meanwhile we can do some privileged register reads and other calculations, essentially for free. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Refine register window trap handling.David S. Miller
When saving and restoing trap state, do the window spill/fill handling inline so that we never trap deeper than 2 trap levels. This is important for chips like Niagara. The window fixup code is massively simplified, and many more improvements are now possible. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Add explicit register args to trap state loading macros.David S. Miller
This, as well as making the code cleaner, allows a simplification in the TSB miss handling path. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fix race in LOAD_PER_CPU_BASE()David S. Miller
Since we use %g5 itself as a temporary, it can get clobbered if we take an interrupt mid-stream and thus cause end up with the final %g5 value too early as a result of rtrap processing. Set %g5 at the very end, atomically, to avoid this problem. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Fix bogus flush instruction usage.David S. Miller
Some of the trap code was still assuming that alternate global %g6 was hard coded with current_thread_info(). Let's just consistently flush at KERNBASE when we need a pipeline synchronization. That's locked into the TLB and will always work. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Elminate all usage of hard-coded trap globals.David S. Miller
UltraSPARC has special sets of global registers which are switched to for certain trap types. There is one set for MMU related traps, one set of Interrupt Vector processing, and another set (called the Alternate globals) for all other trap types. For what seems like forever we've hard coded the values in some of these trap registers. Some examples include: 1) Interrupt Vector global %g6 holds current processors interrupt work struct where received interrupts are managed for IRQ handler dispatch. 2) MMU global %g7 holds the base of the page tables of the currently active address space. 3) Alternate global %g6 held the current_thread_info() value. Such hardcoding has resulted in some serious issues in many areas. There are some code sequences where having another register available would help clean up the implementation. Taking traps such as cross-calls from the OBP firmware requires some trick code sequences wherein we have to save away and restore all of the special sets of global registers when we enter/exit OBP. We were also using the IMMU TSB register on SMP to hold the per-cpu area base address, which doesn't work any longer now that we actually use the TSB facility of the cpu. The implementation is pretty straight forward. One tricky bit is getting the current processor ID as that is different on different cpu variants. We use a stub with a fancy calling convention which we patch at boot time. The calling convention is that the stub is branched to and the (PC - 4) to return to is in register %g1. The cpu number is left in %g6. This stub can be invoked by using the __GET_CPUID macro. We use an array of per-cpu trap state to store the current thread and physical address of the current address space's page tables. The TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this table, it uses __GET_CPUID and also clobbers %g1. TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load the current processor's IRQ software state into %g6. It also uses __GET_CPUID and clobbers %g1. Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the current address space's page tables into %g7, it clobbers %g1 and uses __GET_CPUID. Many refinements are possible, as well as some tuning, with this stuff in place. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[SPARC64]: Move away from virtual page tables, part 1.David S. Miller
We now use the TSB hardware assist features of the UltraSPARC MMUs. SMP is currently knowingly broken, we need to find another place to store the per-cpu base pointers. We hid them away in the TSB base register, and that obviously will not work any more :-) Another known broken case is non-8KB base page size. Also noticed that flush_tlb_all() is not referenced anywhere, only the internal __flush_tlb_all() (local cpu only) is used by the sparc64 port, so we can get rid of flush_tlb_all(). The kernel gets it's own 8KB TSB (swapper_tsb) and each address space gets it's own private 8K TSB. Later we can add code to dynamically increase the size of per-process TSB as the RSS grows. An 8KB TSB is good enough for up to about a 4MB RSS, after which the TSB starts to incur many capacity and conflict misses. We even accumulate OBP translations into the kernel TSB. Another area for refinement is large page size support. We could use a secondary address space TSB to handle those. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-04[SPARC64]: Replace cheetah+ code patching with variables.David S. Miller
Instead of code patching to handle the page size fields in the context registers, just use variables from which we get the proper values. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!